THE EFFECT OF INTRODUCTION OF UMBILICAL DOPPLER RECORDINGS TO OBSTETRIC PRACTICE

Objective To assess the effect on obstetric practice of clinician access to umbilical artery Doppler ultrasound results. Design Randomised controlled trial. Setting A large teaching hospital. Subjects Two thousand two hundred and eighty-nine pregnancies defined as being at risk by referral for Doppler or fetal monitoring. Interventions Continuous wave Doppler studies of umbilical artery. Results immediately available to clinicians. Main outcome measures Fetal outcome: perinatal mortality, Apgar score and admission to the neonatal unit. Obstetric intervention: admission to hospital, induction of labour and caesarean section. Use of tests of fetal well being: cardiotocography, biophysical profile and ultrasound biometry. Results The treatment and control groups were comparable in age, parity, gestation at point of entry and risk features. There were no overall differences in perinatal outcome, obstetric intervention or use of fetal monitoring. Examination of a subset recruited only because of hypertension or suspected intrauterine growth retardation (n = 754) similarly showed no difference attributable to group randomisation. Comparison of only those pregnancies retrospectively defined as low risk and high risk showed more use of cardiotocography in the high risk group with access to Doppler (P = 0.007) but no difference in the low risk group. Conclusion Doppler umbilical artery recording has been shown to perform well in prediction power of antenatal fetal compromise. What has been examined in this study is the response of clinicians to the test. The results suggest that obstetricians do not use the test to modify their risk assessment, and, therefore, the need for fetal monitoring in particular pregnancies. There is a real need for accumulation of information from very large data sets, particularly in the prediction power of Doppler for antenatal fetal compromise from apparently chronic utero-placental cause to guide use of monitoring resources. If simply added to existing fetal monitoring techniques in a hospital where these are widely used, then umbilical artery Doppler recordings may at present simply involve extra resources of staff and expenses, without benefit.